Harmonious is the most consistant dps without aggro, couple nifty debuffs. Only line that gets advanced finisher without a cooldown  timer (1 extra kick line).

Drunken provides some utility as an off-tank, high dps, high aggro (FD 5+ times when max dps'ing in groups with decent tank). Hard hitting and advanceded thousand fist finishers (2 extra).

Dragon is not really playable now tbo, lowest dps by far, and no real advantages to playing one, aside from Invisbility at 46 (can be done cheaply by potions for other path choices).

So I'd suggest drunken or harmonious depending on your playstyle. You can also do a quest to switch between the 3 paths if you aren't happy with your choice. Takes about an hour to 90 mins to do this quest, no mob killing required so do-able at any level.